The history of organ donation is one of crossing lines and moving boundaries. From surgical and pharmaceutical advances that led to longer graft survival and the ability to transplant HLA mismatched organs, to the transplantation of vascularized composite tissues such as upper extremities, uteruses, and faces, the line between the impossible and the possible has shifted over time. The limits of what is considered permissible in organ transplantation also have changed. For decades, organs from deceased donors came solely from individuals previously declared dead using neurological criteria. Donation after circulatory death (DCD) protocols changed this. DCD raised numerous questions about what is and is not permissible. The amount of time a physician should wait between asystole and declaring death, for example, varies among institutions and has been scrutinized in the ethics literature as has the permissibility of interventions to facilitate donation on potential donors prior to death.^{Reference Veatch1} One of the more controversial line crossings in DCD history involved obtaining hearts for transplantation at Denver Children's Hospital after the donors were declared dead using cardio-respiratory criteria.^{Reference Boucek2} Because the hearts re-started after transplantation, some questioned whether the donors had experienced “the irreversible cessation of circulatory and respiratory functions.”^{Reference Bernat3} This fact and the decision to wait only 75 seconds after the heart stopped to declare death raised the question: were the donors dead prior to donation?

In considering the suitability of different types of living donors, including the permissibility of death by organ donation, Lainie Friedman Ross and J. Richard Thisthlethwaite challenge us to examine the ethical boundaries around living organ donation practices and the importance of establishing limits in the face of a desire to make more organs available for transplantation.^{Reference Ross and Thistlethwaite4} Living organ donation already reflects multiple line-crossings or boundary shifts. Ordinarily, surgeons do not remove healthy organs and expose individuals to the risks of surgery for no prospect of direct physical benefit to the individual. Surgery typically is used to treat physical conditions in the surgical patient. Not so in living organ donation. The donor assumes physical risks and bodily harm for the benefit of others, although some donors experience psychosocial benefits.^{Reference Clemens5} Discussion continues about the level of risk to which living donors may be exposed, which has implications for deciding which organs may be obtained from living donors and whose understanding of risks and potential benefits should inform such judgments.

At one time, living organ donation was reserved for close biological relatives. The sphere of permissible recipients now includes persons known to the donor, typically more distant or biologically unrelated family members or friends, and strangers.⁶ Related to this expansion are changes in what donors may receive in exchange for their donation. Originally, donors could receive nothing in exchange for their donation. Now, they may receive the promise of a transplant for another person through paired exchanges or chains, and in some places, a voucher for future use by their designee.^{Reference Cherry7}

Relaxing the medical criteria for being a suitable donor has expanded the pool of eligible living and deceased donors. Persons with life-limiting conditions, such as those Ross and Thistlethwaite discuss, now sometimes may be donors, further increasing the donor pool. Ross and Thistlethwaite explore other ways in which the pool of living donors could be increased such as by allowing death by organ donation. The line prohibiting death by organ donation should not be crossed, they argue, because death by organ donation “circumvents important safeguards: the separation of patient care and patient care decisions from organ procurement as well as the separation of the determination of death from organ procurement. These separations are important to ensure respect for the dying patient and to maintain patient and community trust in the transplant enterprise, and the medical system more broadly.”⁸ Their conclusion that this boundary must be fixed and the reasons they offer challenge us to consider whether these requirements always are met today and whether they always ought to be respected.

Some scholars would argue the line prohibiting death by donation routinely is crossed. Anyone who rejects the claim that someone who meets the neurological criteria for determining death is dead or who disputes the reliability of “brain death” diagnoses could argue that at least some “dead donors” are not dead prior to donation.^{Reference Shewmon9} Among them, some might argue that it is permissible to remove organs from persons who have been diagnosed dead using neurological criteria even though they are not dead, while others would not because they believe that the so-called Dead Donor Rule demands respect.^{Reference Khushf10}

Societies with legal euthanasia already have crossed the line barring physicians from directly causing death. Death via organ donation would constitute a different method for implementing an already-accepted practice in such societies. Once physicians may end patients' lives through lethal injections, for example, perhaps other mechanisms are permissible as well. Defenders of euthanasia often invoke autonomy and the right to make decisions about the timing and manner of one's death. Death by organ donation is another logical application of such claims.^{Reference Wilkinson and Savulescu11} Just as in DCD the decision to withdraw life-sustaining interventions must be made independently of and prior to organ donation decisions, euthanasia decisions could be made prior to discussion of death by organ donation. The emphasis on autonomy, particularly in jurisdictions where persons who are not terminally ill may be euthanized, might mean that even decisions to be euthanized so that one may be a donor should be accepted. In that case, insisting on the separation of organ donation and euthanasia decisions would be inappropriate.

Among the objections Ross and Thistlethwaite have to death by organ donation are possible loss of trust in organ transplantation and surgeon reluctance or refusal to cause donor death.¹² Knowing that transplant surgeons may cause death could undermine trust in organ transplantation, but this is an empirical question and not a moral argument. Whether that fear is founded and, if so, whether it justifies prohibiting willing participants from engaging in the practice or whether that trust could be maintained in other ways, are separate questions.^{Reference Nair-Collins13} Most likely, some surgeons would not want to participate in death by organ donation, and they could be allowed to refuse participation. Such refusals might be rejected, however, just as many object the permissibility of similar exceptions in the case of abortion.

Ross and Thistlethwaite consider the limits of living organ donation and articulate boundaries that would prohibit death by organ donation. Establishing the grounds for accepting or rejecting this and other proposed line crossings or boundary shifts in organ transplantation will be important in the ongoing effort to increase the availability of organs for transplantation in the United States and around the world. Possible changes include various forms of incentives and compensation for living and deceased donation, abandoning the dead donor rule, and revising the definition of death, among others.